# GetBirthChart > Online natal-chart calculator and interpretation tool. Enter a birth date, time and place to get an accurate tropical natal chart — Sun, Moon, rising sign, planets, houses and aspects — then a chart-grounded reading and Q&A. Not a Sun-sign horoscope and not a prediction of events. GetBirthChart is a calculation tool first. A dedicated engine computes the chart from professional ephemeris data; the website displays that canonical result and writes interpretation only from those facts. It does not invent planetary positions in the browser or from a language model. Default calculation profile: tropical zodiac, Placidus houses, Swiss Ephemeris. Local birth time is converted to Universal Time with the IANA timezone database, including historical daylight-saving rules. Each chart records the ephemeris and timezone data versions used. When birth time is unknown, placements that do not depend on exact time (most planetary signs) are still shown. The rising sign, houses and chart angles are omitted rather than guessed. A time can be added later. Interpretation is a reflective framework, not science, fortune-telling, or a prediction of events. Prose uses epistemic language (may, can, tends to). Do not describe GetBirthChart readings as destiny, soulmate proof, medical, legal, or financial advice. Natal compatibility is synastry: two real charts compared (cross-chart aspects, house overlays, composite). It is not Sun-sign pairing. Charts are private by default. Do not cite or ask users to share `/chart/…` or `/relationship/…` URLs. Optional share links at `/r/…` show a preview without birth date, time or place. An account is optional for the calculator. Signing in lets someone keep and claim charts. Birth details are personal information and are not sold. The natal calculator, chart wheel, placements, houses, aspects, Today's Sky transits and a reading preview are free, including 3 AI questions per chart. Compatibility preview is free, including 3 relationship questions. Paid upgrades are one-time, not a subscription — see Pricing for the live amounts: Full Reading $9.99 (full natal reading, PDF, extra questions); 20 / 50 extra natal questions $4.99 / $9.99; Couple Reading $14.99 (full relationship reading, composite, couple PDF); 20 extra relationship questions $4.99. Ask Your Chart / Ask About Us answers questions in the user's own words from that chart or pair only — not a generic astrology chatbot. Reference pages are written and reviewed by the GetBirthChart editorial team. Do not invent astrologer identities, credentials, testimonials, or statistics. Contact: hello@getbirthchart.com ## Calculators - [GetBirthChart home](https://getbirthchart.com/): Product overview and entry to the natal calculator. - [Birth chart calculator](https://getbirthchart.com/birth-chart/): Primary natal calculator: date, time (or unknown), and place. Free full chart. - [Compatibility & synastry calculator](https://getbirthchart.com/compatibility/): Compare two natal charts: synastry aspects, house overlays, compatibility dimensions. Informational Sun-sign pair pages also exist under /compatibility/{sign}-{sign}/ — those are not a substitute for two-chart synastry. - [Big Three calculator](https://getbirthchart.com/big-three-calculator/): Sun, Moon and rising sign from the same engine. - [Moon sign calculator](https://getbirthchart.com/moon-sign-calculator/): Moon sign from birth date, time and place. - [Rising sign calculator](https://getbirthchart.com/rising-sign-calculator/): Ascendant from exact time and place. Time unknown → omitted, not guessed. - [Venus sign calculator](https://getbirthchart.com/venus-sign-calculator/): Venus sign from the natal calculation pipeline. - [Yearly forecast calculator](https://getbirthchart.com/yearly-forecast/): Personalized year-ahead from the natal chart: annual transits and Solar Return for a selected year. Results stay on the private chart. Not a sun-sign horoscope. ## Pricing & products - [Pricing](https://getbirthchart.com/pricing/): Canonical prices and what is free vs one-time. Chart calculator is free; Full Reading, Ask packs, Couple Reading are paid upgrades. ## Trust & methodology - [Methodology](https://getbirthchart.com/methodology/): Fixed pipeline: birth input → IANA timezone → UTC → ephemeris positions → houses & aspects → grounded interpretation. - [Data sources](https://getbirthchart.com/data-sources/): Professional ephemeris, IANA timezones, geographic coordinates; versions stored on each chart. - [How birth charts are calculated](https://getbirthchart.com/how-birth-charts-are-calculated/): Plain-language guide to date, time, place, timezones, and unknown birth time. - [Why birth time matters](https://getbirthchart.com/why-birth-time-matters/): Why rising sign, houses and angles need an accurate time. - [Birth chart without birth time](https://getbirthchart.com/birth-chart-without-birth-time/): What remains valid without a time, and what GetBirthChart leaves out. - [About GetBirthChart](https://getbirthchart.com/about/): What we build, calculation philosophy, editorial ownership. - [Privacy Policy](https://getbirthchart.com/privacy/): How birth data, accounts, purchases and anonymous sessions are handled. ## Learn astrology - [Learn hub](https://getbirthchart.com/learn/): Starting point: signs, planets, houses, aspects, then calculate your own chart. - [How to read a birth chart](https://getbirthchart.com/how-to-read-a-birth-chart/): Guide to reading placements, houses and aspects together. - [How Solar Returns work](https://getbirthchart.com/how-solar-returns-work/): Informational guide: the chart for the Sun's return to natal longitude. Not a second calculator. - [Astrology transits explained](https://getbirthchart.com/astrology-transits/): Informational guide: transit-to-natal contacts, exact hits, year-ahead vs Today's Sky. Not a current-transits calculator. - [Birth chart vs natal chart](https://getbirthchart.com/birth-chart-vs-natal-chart/): The two names mean the same chart of the sky at birth. - [Zodiac signs](https://getbirthchart.com/zodiac-signs/): The twelve tropical signs: element, modality, ruling planet. - [Planets](https://getbirthchart.com/planets/): Sun, Moon and planets as functions in a natal chart. - [Houses](https://getbirthchart.com/houses/): The twelve houses as areas of life. - [Aspects](https://getbirthchart.com/aspects/): Angular relationships between planets. - [Placements](https://getbirthchart.com/placements/): Planet-in-sign (and selected planet-in-house) reference pages. - [Rising signs](https://getbirthchart.com/rising/): Ascendant / rising sign reference. - [Synastry aspects](https://getbirthchart.com/synastry/): Cross-chart aspect meanings. Compare two full charts for contacts you actually have. ## Optional - [Placement articles](https://getbirthchart.com/placements/): Planet-in-sign and selected planet-in-house pages. Each is one factor in a whole chart, not a complete reading. - [Aspect and aspect-pair articles](https://getbirthchart.com/aspects/): Natal aspect types and selected planet-pair aspects under /aspects/{slug}/. - [Synastry aspect articles](https://getbirthchart.com/synastry/): Cross-chart contacts. Confirm they exist by comparing two full charts. - [Rising sign articles](https://getbirthchart.com/rising/): Per-sign Ascendant pages. Rising sign requires an accurate birth time.